The present invention relates generally to valves and more particularly relates to butterfly valves and flow switches especially for use in a fire suppression system.
In a typical fire suppression water sprinkler system as installed in many buildings, an array of individual fire sprinklers is supplied with water through a main conduit and various branch conduits. The individual fire sprinklers are generally provided with a member that melts when the ambient temperature reaches a predetermined level indicative of a fire. The melting of the member opens a fire sprinkler to spray water in order to suppress the fire. The individual fire sprinklers are provided with meltable members so that the spray of water will hopefully be limited to the region of the building where the fire is present. In this way, the extent of water damage may be minimized.
After a fire, and especially during maintenance and renovation, it may become necessary to replace one or more of the individual water sprinklers. At such times it is desirable to be able to drain the system of water conduits, so that the removal of one or more of the individual water sprinklers will not result in a flow of water through the fitting for the water sprinkler. Accordingly, it is conventional in the art to provide a valve which controls the flow of water to the arrangement of individual water sprinklers.
Such fire suppression systems also oftentimes have a switch or sensor that detects the flow of water in the conduits to indicate that even only one of the individual water sprinklers has opened. Since the flow of water in the conduits generally means that a fire is present in the building, the switch or sensor typically triggers a fire alarm or sends an appropriate signal directly to a fire department. Therefore, many fire codes require, and it is otherwise desirable, that the switch or sensor which detects the flow of water in the conduits be periodically tested.
The use of a separate control valve and flow switch results in significant time and expense during the installation of such plumbing.
Accordingly, it is an object of the present invention to provide a valve having an integral flow switch.
Yet another object of the present invention is to provide a butterfly valve and flow switch especially for a fire suppression water sprinkler system.
Still another object of the present invention is to provide a butterfly valve and flow switch which is relatively simple and easy to install and use.
These and other objects are accomplished by a valve and flow switch according to the present invention.
The valve and flow switch according to the present invention comprises a valve housing having an inlet and an outlet. A valve member is mounted for movement about an axis of rotation between an open position in which the disk permits flow from the inlet to the outlet and a closed position in which the disk prevents flow from the inlet to the outlet. A passageway is provided from one side of the disk to an inlet of a flow switch with an outlet of the flow switch communicating with the outlet of the valve.
In the preferred embodiment of the present invention, the valve is a butterfly valve with the valve member being a disk. The passageway has an inlet which is provided on a side of the disk which is facing toward the outlet of the valve when the disk is in the closed position. In addition, the passageway preferably is provided along the axis of rotation of the disk. If desired, the outlet of the flow switch may have an arrangement to provide a relatively low pressure at the outlet of the flow switch in order to facilitate flow through the flow switch. In addition, a port may be provided in the outlet of the valve to receive a pressure gauge. If desired, one or more sight glasses may be provided in the outlet of the valve and a tapping may be provided to receive an inlet of a pressure relief valve.
In operation, when the disk is in the closed position, communication is prevented between the inlet of the valve and the outlet of the valve. No flow is permitted into the passageway from the inlet of the valve when the disk is in the closed position. When the disk is moved to the open position, communication is permitted between the inlet and the outlet and flow is also permitted from the inlet of the valve into the inlet of the passageway leading to the flow switch.
When there is no flow from the inlet of the valve to the outlet, there will be no flow from the inlet of the passageway through the flow switch. When there is a flow from the inlet to the outlet of the valve, there will also be a flow through the passageway to the flow switch and back to the outlet of the valve and the flow switch will signal that a flow is occurring through the valve.